Push buttons and push-button devices of the type mentioned in the introduction are used, for instance, but by no means exclusively, in motor vehicles in the passenger compartment or within easy reach of the driver. Such push buttons are used in such applications to actuate a great variety of technical systems and means on the motor vehicle, for example, the air conditioner, window lifter, seat adjustment and the like.
An electrical contact is frequently actuated by such push buttons and the electric signal thus generated activates the intended function of the system to be controlled. The relative arrangement in space of the technical system to be controlled and the push button can be selected nearly as desired in such a case of the electrical connection of the push button to the system to be controlled because the flexible electrical connection can be installed extensively freely. The compensation of any dimensional tolerances in terms of the distances between the push button and the technical system to be controlled is also problem-free for the same reason, especially if the push button and the technical system are arranged or mounted on different mechanical carriers.
However, the statements made above are not true especially when there is no electrical connection between the push button and the technical system to be connected, but the technical system is rather in mechanical connection with the push button.
Even though tolerances do not, as a rule, play a major role if the push button and the technical system to be controlled are arranged in one and the same housing or on one and the same mechanical carrier, tolerances will develop, mostly inevitably, between the installation site of the push button and that of the technical system as soon as the technical system to be controlled is located on a carrier different from that on which the push button used for the control is located.
For example, push buttons on the motor vehicle are frequently arranged in the area of the instrument panel or in the center console, always essentially in the area of the control surface. However, the technical systems controlled herewith are usually not anchored on the surface of, for example, the instrument panel or the center console, but are rather connected to a carrier that is located under it and is a rigid part of the body or to the body itself.
However, there often are considerable tolerances in the distances between the installation site of the push button and that of the system to be controlled. These tolerances are often in the range of a few mm in each of the three directions in space, for example, because of the considerable size of components, such as the instrument panel or the center console, because of the plastic materials used for these components, as well as because of tolerances of the body structure itself, and because of other tolerances of the mounting systems used for the assembly.
These distance tolerances between the installation site of the push button and the installation site of the technical system to be controlled must then be compensated by means of a separate setting operation in a complicated manner and hence at a high cost in order to ensure the function of the push-button actuation.
Furthermore, thermal expansions may also occur, which assume quite substantial orders of magnitude in case of the temperature differences occurring in a motor vehicle. The precision of the mechanical connection between the push button and the technical system to be controlled suffers in such a case. Automatic triggering of the function of the technical system or failure of the ability of the technical system to be operated, for example, because of thermal expansions, may occur in the worst case.